Carbon Dioxide Production from Organic Waste Recycled in Controlled Environment Agriculture Systems

Controlled environment agriculture strives to close resource loops while increasing agricultural outputs. Plant factories, and the organic waste they produce, are an ever-increasing reality in the constantly urbanizing world. Aerobically decomposing organic waste at the site of production is one method for reclaiming the fixed carbon in plant residues as carbon dioxide. To understand how the concentrations of carbon and nitrogen, which are both relevant to aerobic composting, in plant residues are affected, an environmental manipulation study was conducted with Green Bush Bean (Phaseolus vulgaris L. cv Bronco). There were no significant changes in the concentration of both elements when grown under differing proportions of blue light and concentrations of nutrient solution. An inexpensive respirometric decomposition system was then built to aerobically decompose various combinations of green bush bean residue with spent peat moss growth substrate. The results indicated that peat moss was exceptionally stable and could be used to (1) modulate the composting dynamics of other feedstocks that contain a higher amount of labile carbon and (2) increase the marketability of the final compost by increasing its water holding capacity and structural integrity.